Lazarus404

L and R provide accurate activity for that sort of thing ;-) Why not branch from there for both output and route to analog input in the Arduino? I don't know what the upper or lower values for those pads are (maybe in the docs?), but it's surely a valid option. Just make sure it doesn't exceed the pins impedance.

Lazarus404

Not necessarily. The analog input in the Arduino can take any value between 0v - 1v (I believe), so, as long as you limit the voltage (using the correct resistance), then you have a simple variable source right there. The biggest issue is making sure your querying of that source doesn't use the potential that would otherwise drive your speaker output (though you could increase that with an amp).

Lazarus404

Yeah, 5v... That's what I meant ;-) Well, you're okay, then, seeing as 5v is the maximum voltage anywhere past the regulator! Hook even one of those pads into the Arduino and use it as an input. Actually, you could also average the highs and lows so as to get better results, as those highs and lows will be quite similar in value.

You have to be careful when using audio signals. The output from the rMP3 on the L and R pins are actually AC signals (because of the filter capacitors on the outputs). This means that the voltage with respect to ground on those pins can be negative, if you connect them to the analog inputs on the Arduino. This can damage the ADC on the Atmel chip.

You could introduce a DC offset, but that will require extra components which I think mowcius is trying to avoid.

I'd stay away from connecting the audio output to one of the analog inputs, unless you know what you're doing.

mowcius - your wish is my command. Here is the updated documentation on the input interface:

Lazarus404

Hadn't thought about it being AC (which should be as obvious as the nose on my face), but it's nothing that a handful of diodes couldn't fix. In fact, one could always route the negative edge to a separate pin as a positive feed.

Lazarus404

Sparkfun's MP3 breakout is far less functional. I really had to search high and low for a "high quality" and flexible MP3 board for my JukeBox project I'm building. There just aren't that many out there. It was pure luck that this one was already arduino compatible, because I was quite prepared to fashion one into an arduino ready product.

I never had a problem with that shield - until I tried to use it. You pay less for more work (and more headaches, and more technical jargon, and so on). If that turns your crank, go for it. The adage always holds true: "You get what you pay for".

I'll put forward a challenge to you though. If you can explain the differences between that board and the Rogue Robotics rMP3 shield, I'll send you a free rMP3 shield. [Offer only valid for Sannin ]

b

P.S. I'll steer clear of the fact that they also use Arduino in their product name when it clearly isn't endorsed by the Arduino Team.

rockylou84

miliatov

I am building a small installation where PIR sensor will detect presence and start playback of two audio files simultaneously at two different locations.

If I stack two rMP3 players on top of one arduino board, will both of the players start playback simultaneously when 'play' command is sent through pin 6, or do I need to rewire pins on the second shields and have a second 'play' command sent through the rewired pin.